Bobebt dodswobth and john w



8 e n .M H TW m T d S n a 8 0 M .u WT 2. .JD &h a H6 D. .RS 0 r W w S Dw0e DEM U 9, M WS 0 u2 M 0 0 M0 m N INVENTGR: A JWQ PatentedApril-5,1881.

ATTORNEYS.

N. PETERS, PHOTO-LITHOGRAPHER, WASHINGTON D C UNITED STATES P TENTOFFICE.

ROBERT DODSWORTH AND JOHN W. HOLDSWORTH, OF ST. LOUIS, MISSOU RI.

MOUTH-PIECE FOR SPEAKING-TUBES AND TELEPHONES.

SPECIFICATION forming part of Letters Patent No. 239,740, dated April 5,1881.

Application filed September 17, 1880. (No model.)

To all whom it may concern:

Be it known that we, ROBERT Donswonrn and JOHN WILLIAM HOLDSWORTH, ofSt. Louis, in the county of St. Louis and State of Missouri, haveinvented a new and Improved Mouth-Piece for Speaking-Tubes andTelephones, of which the following is a specification.

The object of our invention is to dispense with the press-buttons andother separate devices employed in connection with speakingtubes andtelephone-lines, for ringing an electric bell or giving a signalotherwise by electricity.

Our invention consists in combining the circuit-closing devices with thecover of the mouth-piece of the tube or telephone in such a manner thatwhen the cover is opened the circuit shall be momentarily closed to givethe signal.

In the accompanying drawings, forming part of this specification, Figure1 is a rear eleva tion of a mouth-piece and plate embodying ourinvention. Fig. 2 is a vertical section of the same on line as x of Fig.1, with the cover open. Fig. 3 is a similar view with the cover closed.

Similar letters of reference indicate corresponding parts.

A is a plate formed with mouth-piece a, as usual, for use in connectionwith speakingtubes ortelephone-instruments.

b is the cover of the mouth-piece, consisting of a plate hung on a studor pivot, c, that has a bearing in plate A,above the mouth-piece, sothat the cover shallfall, by gravity, to close the opening At the backof plate A, above pivot c, is fixed a block, d, preferably ofnon-conducting material, through which block the ends of thecircuit-wires e 6 pass to the under side, and connect, respectively, tothe spring-arms f g, that are attached to block d, and extend back in ahorizontal direction. The end of one arm, f or g, is extended beneaththe end of the other, so that the two ends are contiguous but not incontact.

The inner end of the stud or pivot c is formed with an enlargementhaving two cam-projections, 2', each of which is shaped to pass beneathand raise the lower spring-arm into contact with the other when thecover b is first moved, and release the arm when the cover is fullyraised, and also to pass between the two piece is opened the circuitwill be momentarily closed, and the signal given, and the circuit willremain broken until the cover is closedand again opened. The movement ofthe cover is thus utilized to give a call or signal, which heretoforehas been given by press-buttons or similar devices.

It is evident the mechanism may be differently arranged for closing thecircuit by movement of the cover, and the invention may be applied inconnection with a cover opening outward.

We do not limit ourselves in these details.

Having thus described our invention, we claim as new and desire tosecure by Letters Patent- 1. In telephones, the combination, with themouth-piece a, of a mouth-cover, b, connected with the circuit-closingdevices and swinging laterally to close the circuit, whereby the sidemovement of the cover at one end sounds the alarm at the other, asdescribed.

2. The swinging cover I), having its pivot provided with cam-projectioni, and the springarms f g, connected wlth the wires of an electriccircuit, combined with the mouth-piece of a speaking-tube or telephone,substantially as and for the purposes set forth.

ROBERT DODSWORTH.

JOHN WILLIAM HOLDSWORTH.

Witnesses:

BERNARD P. TAAFFE, F. A. G. MACMANUS.

